1. Technical Field
This invention relates generally to a locking mechanism for mechanically securing two components together, and more specifically to such a locking mechanism that is particularly suitable for locking an accessory device onto a portable telecommunication instrument.
2. History of Related Art
Several arrangements are used for locking accessory devices, such as battery chargers, power supply adapters, hands-free operation adapters, and the like to a base structure, such as a radiotelephone. The locking mechanisms are generally provided on the accessory structure, and typically include one or more molded plastic arms that engage a mating feature on the base structure. The plastic arms are deflected by a user to remove or insert the arms into a mating feature on the base structure, and thereby disconnect or attach the accessory device to the base structure. When the deflecting force applied by the user to the arms is released, the arms spring outwardly thereby secure the accessory device to the base member.
Such molded plastic arm configurations do not hold up well when subjected to repeated deflection, eventually resulting in a loose fit and even breakage of the plastic arm. This problem results in a limited life cycle for the accessory device. Repair of the plastic arms generally requires disassembly of the accessory adapter at a service center. Often repair costs exceed the cost of purchasing a new accessory. Also, such deflectable arm locking mechanisms have heretofore been cumbersome to operate because deflection of the arms is generally accomplished by squeezing two arms toward each other to remove or attach the accessory device. This operation may be difficult for a person having limited manual dexterity.
Other methods currently used to attach an accessory device to a base structure include press-fit designs which typically require significant insertion force. Such press-fit designs are subject to high early wear rates, and are often difficult to secure for proper electrical connection and remove for subsequent disconnection from the mating structure.
The present invention is directed to overcoming the problems set forth above. It is desirable to have a simple, easy-to-use, locking mechanism for attaching an accessory structure to a base structure. It is also desirable to have such a locking mechanism that is releasable in response to depressing a single button which provides positive, tactile feedback to the user. It is also desirable to have such a releasable locking mechanism in which the locking arms are minimally stressed and will withstand repeated deflection over the life of the accessory device.